Art of duplicating



A. E. SCHUTTE 2,140,482

ART OF DUPLICATING Dec. 13, 1938.

Filed Feb. 19, 1935 Patented Dec. 13, 1938 UNITED; STATES PATENT oFFIcs 2,140,482 I ART OF DUPLICATING August E. Schutte, Northboro, Mam, assignor to A. B. Dick Company, Chicago, 11]., a corporation of Illinois ApplicationFebruary '19, 1935, Serial No. 7,156

, 4 Claims.

termed porous typography, and results in a great economy in the duplication of ty matter.

In duplication, as heretofore commonly praclO ticed, a stencil is made from an ink-impervious sheet either by cutting or perforating the sheet to produce openings therein, or by expressing parts of a coating or impregnating composition which has been applied to an open lace-like tissue. I have discovered that it is possible to make the printing member from the fibrous sheet without expressing or otherwise removing any material therefrom, and without the necessity of making any openings or perforations in the sheet. My method consists in re-positionlng partsof the fibrous material of the sheet to provide local inkconductive areas. These areas differ from openings or perforations in that they are valvular in the sense that they conduct ink more easily in '25one direction than in the other.

written In accordance with my invention, the re-positioning of the fibres of a. normally ink-impervious fibrous sheet is effected by the blow of the type of a typewriter. In the form of the method which I find most desirable, the blows of a type cause a limited displacement of local areas of the sheet from the plane of thesheet. This effects the reorientation of the fibres to make these areas ink-conductive, and also produces embossed potons projections which may be filled -with-ink and then .pressed to squeeze the ink upon corresponding areas of a sheet on which a print is made. i

A complete understanding-of my invention may best be had from a detailed description in connection with the annexed diagrammatic drawing which is enlarged sectional .views of my n printing member: a

Fig. 1 shows the blank from which the printing member is made;

.Fig. 2 indicates the making ofthe blank into a printing member; Fig. 3 shows another way of making the blank into a printing member; and

member.

The blank shown-in Fig. 1 is afibrous sheet having a smooth normally ink-impermeable front surface 2 and, if desired, although not necessarily,

a similar rear surface 3. The middle portion 4'' of Fig. 4 shows printing by means of the printing the sheet may be normally ink-permeable. The sheet consists of a compact mass of well-beaten fibres which-are in general oriented in directions more or less parallel to the surfaces of the sheet. The fibres are capable of relative movement.

The blank may consist of well-beaten, wellcalendered printing paper impregnated with a viscous liquid. I have found it desirable, al-

though not necessary, to use so-called uncoated paper of this character of the grades rated from fiftypounds to eighty pounds. As the impregnating liquid, I find a viscous oily liquid most desirable. The impregnation renders the fibres of such paper capable of relative movement so that they may be re-oriented rather than mashed or broken .by an impact.

As a specific illustration, I have made a satisfactory blank by thoroughly impregnating with castor oil a printing paper made by the Champion Mills, of Hamilton, Ohio, and identified by them by the name "Garamond Super, '70 Pound Basis. The impregnation changes the character of the paper, giving it the appearance of parchment and rendering its fibres capable of the relative movement hereinafter described.

Figs. 2 and 3 illustrate the making of a printing member from the blank shown in Fig. 1. This is accomplished by striking local areas of r the rear-surface of the blank with hard elements,

such as the types of a typewriter, to re-position the fibres of the-blank in the areas struck, chang.-.

ing at least some of them from their normal orientation parallel to surfaces of the sheet to a position in which theyare re-orlented more transversely to the sheet so that they tend to conduct ink through the sheet. This re-orientation is most desirably accomplished by causing the blows of the type to displace or offset local areas of the sheet from the plane of the sheet to a limited extent. To accomplish this, the blows are struck against the rear surface of the sheet while its front surface is supported by a backing which permits a limited outward movement of local areas of the frontsurface of the sheet. For this purpose, the backing may consist of a thin compressible layer 5 overlying a hard surface 6, as shown in Fig. 2. The layer 5 may be of resilient material such as rubber, in which case it may be used repeatedly; or the layer 5 may consist of non-resilient compressible material such as tissue paper.

Instead of using the yieldable backing shown in Fig. 2-, a rigid backing containing a large number of closely-spaced indentations may be used, as illustrated at l in Fig. 3. In this case, the ex- 9 direction from the back surface to the front surtruded projections on the front surface of the printing sheet are, of course, indented. I have found that fine sandpaper makes a satisfactory backing of the type shown in Fig. 3.

Whichever sort of backing be used, it is im- I sufliciently toburst it open into visible holes.

When using the preferred blank previously described which is rated as seventy-pound paper with a yielding backing such as shown in Fig. 2, the thicknessof the compressible layer 5 should be about three one-thousandths of an inch. It may desirably consist of a sheet of tissue paper rated as eighteen pounds. When the preferred blank is used with a rigid backing as shown in Fig. 3, I find the sandpaper identified as No. 05 to No. 07 most desirable for the backing I.

The striking of the type against the back surface of a printing member whose front surface is supported in the manner described so as to permit limited outward movement of portions thereof has several effects which cooperate in the practice of my method.

One effect is the indentation of the rear sur- 7 face of the printing sheet. This stretc'hes local areas of the rear surface sufficiently to render them permeable to ink, and also provides an open reservoir 8 for the ink, as shown in Fig. 4. Another effect is the stretching of local areas of the front surface of the sheet which renders them ink-permeable.

Another effect is to produce embossed permeable reliefs projecting out from the impermeable front surface of the sheet.

Another effect at the areas struck by the type is the re-orientation of the fibres throughout the thickness of the sheet, changing them from a position parallel to the surfaces of the sheet to a position transverse to the surfaces.

Another effect is" to break the bond between the fibres so shifted in a manner to permit ink to travel along between them.

I Another effect, which is perhaps the combined result of those previously mentioned, is to make the areas struck by the type ink-conductive in the face of the sheet. These areas will, however, not

readily conduct ink in the opposite-direction.

inked from its rear surface, and its front surface is then pressed against the paper on which the impression is to be made. The ink fills the reservoirs provided by the indentations inthe rear surface and passes through .the ink-conducting a eas into the embossed projections on the front s face of the sheet, as illustrated in Fig. 4.

When the embossed projections are pressed I against the impression paper, the ink in them is squeezed out upon the paper, as it cannot easily pass back into the reservoirs. The printing may be done on an ordinary stencil duplicating machine in which the back surface of the printing member is kept in contact with ink-supplying means, while the front surface is brought into contact with sheets of impression paper one after another. This involves alternate application'and release of pressure on the printing member.

When the pressure on the front of the printing member is released, the embossed projections are filled with ink supplied from the ink-supplying means, and, when the pressure is applied, the

ink in these projections is equeezed out on the impression paper. The alternate application and release of pressure, combined with the valvular character of the ink-conductive portions of the printing member, result in a pumping action which is highly effective in moving the ink through the printing member. The printing may be done with any ordinary printing ink. It is, however, desirable, but not necessary, to use an ink somewhat more fluid than that ordinarily used in stencil duplicating.

Printing may be effected by means of my printing member in other manners. The ink may be applied to the rear surface before the impression is made, and the printing member may then be removed from the ink supply and pressed against the impression paper.

It is also possible, and in some cases desirable,

to ink the embossed porous projections from their front or projecting surfaces. This may be done at the time the blank is embossed in the typewriterby using on the backing a yieldable layer impregnated with an aniline dye. In this case, the dye impregnates the embossed projections as they are formed.

Whatever be the manner in which the porous projections are filled with ink, pressing them against an impression paper will squeeze ink out upon the paper.

My invention is not limited to the particular embodiments which have been described, but incorporates any generally impervious sheet provided with localized spongy areas which. are adapted to take up and retain ink and to deposit it locally under pressure, and to the method of duplicating by means of such a sheet which I have termed "porous typograp What I claim is:

l. A printing member, comprising a generally ink-impervious, homogeneous, fibrous sheet con taining valvular, ink-conductive, local areas which permit the passage of ink through them in one direction more freely than in the other direction.

2. A printing member, comprising a fibrous sheet whose fibres are generally oriented parallel to the surface of the sheet and compacted sufficiently to make the sheet generally ink-impervious, and containing portions in which the fibres are oriented transversely of the sheet to provide local, ink-conductive areas.

3. A printing member, consisting of .a sheet of uncoated paper, which of itself is ink-impervious, containing ofi'set, local, imperforate, ink-conductive areas.

4. The method of making a printing plate which consists in impregnating a sheet of wellbeaten, well-calendered paper with oil, placing one surface of the impregnated paper in contact with a compressible layer of material and striking the exposed surface of the paper with type elements with a force sufficient to emboss the paper and make the embossed portions permeable to ink in one direction only.

1 AUGUST E. SQH'U'I'IE. 

